Design and characterisation of the MICE beamline

K.Walaron IOP Warwick April 20K.Walaron IOP Warwick April 200606

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Design and Design and characterisation of the characterisation of the

MICE beamlineMICE beamline K. WalaronK. Walaron

University of GlasgowUniversity of Glasgow


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Neutrino Factory physics (very Neutrino Factory physics (very quickly)quickly)

231312231312231223131223

231312231312231223131213

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MNS

• Neutrinos have mass and Neutrinos have mass and mix. mix.

• First conclusive evidence of First conclusive evidence of physics beyond the physics beyond the standard modelstandard model

• Theta13, mass hierarchy Theta13, mass hierarchy and possibly leptonic CP and possibly leptonic CP violation needs investigatedviolation needs investigated

• Theta13 Theta13 nu_e to nu_mu nu_e to nu_mu oscillation. oscillation.

Mass hierachy Mass hierachy change in change in osc. Prob. Between nu and osc. Prob. Between nu and nu bar (MSW)nu bar (MSW)


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The Neutrino FactoryThe Neutrino Factory

• Proton DriverProton Driver

4MW4MW, , 10^21 Muon Decays10^21 Muon Decays

• Target and Pion CaptureTarget and Pion Capture

Huge power densities, 20 T Huge power densities, 20 T solenoidsolenoid

• Phase Rotation & CoolingPhase Rotation & Cooling

Reduce momentum Reduce momentum spread/transverse emittancespread/transverse emittance

• AccelerationAcceleration

Linacs, RCL’s, FFAG to 8~50 Linacs, RCL’s, FFAG to 8~50 GeVGeV

• StorageStorage

Triangular, Racetrack, Triangular, Racetrack, dogbone etcdogbone etc

To G Sasso

To Soudan

[ 900–1000 m below ground ]

3 × FFAGs 3–8 GeV

8–20 GeV20–50 GeV

3 GeV linac

Cooling

Phase rot.

Target

~10 GeV synch. + booster + linac

To G Sasso

To Super-K (1000 m,

projection)

To G Sasso (100 m)

To Soudan (500 m)Return leg

Return leg (vertical)


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Muon CoolingMuon Cooling

0

2

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014.0

2

11

XmEE

d

ds

dE

ds

d nn

C• Transverse emittance is defined asTransverse emittance is defined as

Where C is the 2N*2N matrix of covariances (Xi, Xj) with elements Cij = Covariance (XiXj) Where C is the 2N*2N matrix of covariances (Xi, Xj) with elements Cij = Covariance (XiXj) with Xi being an element of the 6D phase space vector (x, px, y, py, t, E)with Xi being an element of the 6D phase space vector (x, px, y, py, t, E)

• The normalised transverse emittance measurement relevant to MICE is:The normalised transverse emittance measurement relevant to MICE is:

• Physics requirement for MICE is a reduction of tranv. Norm. Emitt. by >10% +/- 0.1% for Physics requirement for MICE is a reduction of tranv. Norm. Emitt. by >10% +/- 0.1% for (140-240 MeV/c) muon beam(140-240 MeV/c) muon beam


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MICE (just as quickly)MICE (just as quickly)

• Emittance Emittance measurement measurement carried out by carried out by SciFi trackersSciFi trackers

• 3 liquid H 3 liquid H absorbers to absorbers to reduce Preduce P

• Pz component Pz component replaced by 8 RF replaced by 8 RF cavities. 8MV/mcavities. 8MV/m


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Design requirements of the Design requirements of the beamlinebeamline

• Muon purity. Pion/Muon momentum Muon purity. Pion/Muon momentum separation should be as large as separation should be as large as possiblepossible

• To provide a tuneable emittance To provide a tuneable emittance muon beam to MICEmuon beam to MICE

• TOF0 to TOF1 minimum separation of TOF0 to TOF1 minimum separation of 6.94m.6.94m. Providing muon Providing muon identification.identification.


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General layout: MICE General layout: MICE beamlinebeamline


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Evolution of beamlineEvolution of beamline• Initial design carried out using Transport Initial design carried out using Transport

and Turtle codesand Turtle codes

• New design modelled using Geant4 based New design modelled using Geant4 based program called G4Beamline.program called G4Beamline.

• Beamline evaluated: Detector rates, TOF Beamline evaluated: Detector rates, TOF separation, beam match, beam scraping separation, beam match, beam scraping etc.etc.

• If needs be back to the drawing If needs be back to the drawing board(Transport and Turtle)board(Transport and Turtle)


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Example tune Example tune (AUG05, 240 (AUG05, 240 MeV/c)MeV/c)

• Show details from my Show details from my AUG05 240 MeV/c tune.AUG05 240 MeV/c tune.

• Tune is based on a 200 Tune is based on a 200 MeV/c, 6pi mm mrad MeV/c, 6pi mm mrad design with currents design with currents scaledscaled

• Not a final tune, changes Not a final tune, changes have been made to the have been made to the magnet/ detector magnet/ detector positions within the hall positions within the hall since. Changes the since. Changes the magnetic lattice magnetic lattice considerably. New tunes considerably. New tunes being developed as we being developed as we speak.speak.

Q1-Q3

D1

Decay Solenoid

Proton Absorber

D2

Collimators

Q4 – Q6 Q6 – Q9

TOF0CKOV1 TOF0

High Z diffuser


1010

Sample X, Y beam profileSample X, Y beam profile


1111

Sigma xSigma x

Q4

TO

F0C

KO

V1

Q7

Q8

Pre

-TO

F1Post

-TO

F1Le

ad

diff

use

r

Pre

ben

d2

an

d a

bso

rber

Colli

mato

r


1212

Sigma YSigma Y

Q4

TO

F0C

KO

V1

Q7

Q8

Pre

-TO

F1Post

-TO

F1Le

ad

diff

use

r

Pre

ben

d2

an

d a

bso

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Colli

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TransmissionTransmission

Q4

TO

F0C

KO

V1

Q7

Q8

Pre

-TO

F1Post

-TO

F1Le

ad

diff

use

r

Pre

ben

d2

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d a

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Ptot immediately downstream Ptot immediately downstream of lead diffuserof lead diffuser


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4D emittance4D emittance

Q4

Q5

Q6

TO

F0C

KO

V1

Q7

Q8

Pre

-TO

F1Post

-TO

F1Le

ad

diff

use

r

Pre

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d2

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Rates at beamline detectorsRates at beamline detectors• 100k Pi+ at target.100k Pi+ at target.• The rates for this tune The rates for this tune

assuming the tuned pion assuming the tuned pion momentum and momentum momentum and momentum spread of 500.42+/-17 MeV/c spread of 500.42+/-17 MeV/c flat.flat.

• Rates are normalised to a Rates are normalised to a MARS target simulation.MARS target simulation.– Assumptions made about Assumptions made about

targettarget– Assumptions made about Assumptions made about

ISISISIS– ISIS target interaction big ISIS target interaction big

unknown for MICEunknown for MICE

TOF0TOF0 0.9865 MHz0.9865 MHz

CKOV1CKOV1 0.8972 MHz0.8972 MHz




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Matching of beamline into Matching of beamline into MICEMICE• Beamline automatic Beamline automatic

optimiser recently optimiser recently devellopeddevelloped

• Uses minuit SIMPLEX Uses minuit SIMPLEX engine to optimise engine to optimise quadrupole currents quadrupole currents along muon matching along muon matching section.section.

• Matches to beta Matches to beta function inside first function inside first SciFi trackerSciFi tracker

• Will in time be adapted Will in time be adapted to include beam to include beam diffuser thicknessdiffuser thickness


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1919

Reduct

ion o

f 45m

m


2020

MICE target testMICE target test

• Beam conditions at target insertion point not well known Beam conditions at target insertion point not well known both transversely and longitudinally (beam evolution over both transversely and longitudinally (beam evolution over ~2ms)~2ms)

• Every rate ever quoted in beamline studies suffers from Every rate ever quoted in beamline studies suffers from this. (Assumptions in transverse density/ how much of the this. (Assumptions in transverse density/ how much of the beam we intercept). IMPORTANT, especially for TOF0.beam we intercept). IMPORTANT, especially for TOF0.

• LAHET, GEANT4 and LAHET target simulations all differ in LAHET, GEANT4 and LAHET target simulations all differ in pion yields (~ 20%)pion yields (~ 20%)

• Need to always be careful not to take too much of the beam Need to always be careful not to take too much of the beam and incur the wrath of ISIS. Correlate pion yield with beam and incur the wrath of ISIS. Correlate pion yield with beam lossloss

• Aim to investigate this in a beam/target study in Summer Aim to investigate this in a beam/target study in Summer 20062006


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Scintillator SchemeScintillator Scheme

High Rate

Provide coincidence to reduce neutrons. Measure proton depleted rate.

Ranges out low energy scattered protons

20m from target

5cm

• Need to Need to measure measure particle yields particle yields as a function as a function of target of target insertioninsertion

• Momentum Momentum and flux and flux depends on depends on dipdip

• Need to know Need to know numbers of numbers of pions/protons pions/protons by counting by counting and dE/dx in and dE/dx in scintillator.scintillator.


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ConclusionConclusion

• On track to have on the floor a On track to have on the floor a beamline that can be tuned to beamline that can be tuned to produce a selection of beams by end produce a selection of beams by end of this yearof this year

• MICE then coolsMICE then cools

• Build a Neutrino FactoryBuild a Neutrino Factory

• Easy!! Easy!!

Documents

Design and characterisation of the MICE beamline